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THE CUBA REVIEW 



CULTIVATED SOILS IN CUBA AND OTHER COUNTRIES 



In Cuba there are not found distinctly 

 wet and dry districts as in Porto Rico and 

 Hawaii, and therefore there is more uni- 

 formity of soil types and soil conditions. 

 In the western part are found the old plan- 

 tations situated on the easily cultivated 

 soils of limestones foundation. They have 

 practically no subsoil, and although deep 

 plowing is not practiced, this is more the 

 result of indifference than of any well- 

 defined efforts at soil improvement. Other 

 soils are similar to those of Porto Rico 

 which have a like origin, those of Cuba 

 being as a rule deeper and fresher. 



One of the most important constituents 

 of cultivated soils, whether considered from 

 its physical or chemical effect, is lime. 



In the natural decay of vegetable matter 

 in the soil, acids are produced which if not 

 neutralized will seriously interfere with 

 subsequent growth, especially of the ordi- 

 nary field crops. These acids interfere 

 chiefly by preventing the growth of bacteria 

 which render available the organic material 

 in the soil. A very small amount of nitrates 

 is found in acid soils, and therefore the 

 plants do not thrive because of this lack 

 of nitrogen. This is noticed particularly 

 in the case of sugar cane, which is ver\' 

 dependent on an adequate supply of avail- 

 able nitrogen for its best development. 



The best sugar-cane soils both of Hawaii 

 and Cuba are those in which there is a 

 large percentage of lime. In the former 

 case the soils are derived from basaltic 

 lava in a large measure, and in most cases, 

 when the rainfall is slight, the lime con- 

 tent is sufficient. On the other hand, in 

 districts of large rainfall the lime has been 

 dissolved and washed out to such an extent 

 that dressing of ground limestone, coral 

 sand from the seashore, or caustic lime 

 are made at frequent intervals. This is 

 especially the case in the Hile district where 

 the rainfall is 150 inches or more per year. 

 In Cuba the lands are largely derived from 

 limestone, and therefore this element rarely 

 has to be supplied to the soil. Indeed. I 

 am persuaded that the great and lasting 

 fertility of Cuban cane soils is due in a 

 large measure to the large lime content 

 and to the fact that the cane trash is rarely 

 burned off. This latter adds the organic 

 matter necessary, and in the presence of 

 carbonate of lime the nitrogenous material 

 is changed to soluble nitrates which are so 

 much needed by the plant. This explains 

 also why the Cuban planter has been able 

 to raise large annual crops of cane without 



the use of commercial fertilizers. The lime 

 also assists in keeping the soil open and 

 promotes deep root development, thus 

 maintaining a good depth to the surface 

 soil. 



There is an erroneous impression prev- 

 alent among many farmers that if a heavy 

 rain follows an application of fertilizers 

 the latter are washed out of the soil and 

 lost. This onh- happens when the fer- 

 tilizers are dissolved, and bodily washed off 

 from the surface of the soil. Where the 

 fertilizers have been covered with earth, 

 or where they rest on loose earth, so that 

 the water after dissolving the ingredients 

 passes down through the soil and into the 

 subsoil, the phosphates, sulphate of potash 

 and ammonia compounds are absorbed or 

 fixed by the soil. The very basic soils of 

 Haw-aii were found by the writer to possess 

 this property to a remarkable degree. This 

 investigation was undertaken to determine 

 if fertilizers to any notable exception are 

 lost when they are left uncovered in the 

 cane rows, followed by heavy irrigation, 

 which is the usual practice in those islands. 



It was found that even with an irrigation 

 of 6 inches of water most of the fertilizers 

 were fixed in the first 6 inches of the soil. 

 Subsequent irrigations wash out both nitro- 

 gen and potash in decreasingh' smaller 

 quantities, as can be seen by making analy- 

 sis of the drainage waters, or waters of 

 streams, which is no more than drainage 

 water from the area of its origin. 



Nitrogen in the form of nitrate of soda, 

 on the other hand, is washed out of the 

 soil, since it is not fixed. Indeed, nitrates 

 were found increasing in quantity at a 

 depth of 6 feet soon after irrigation under 

 plantation conditions. These results led to 

 the recommendation that mixed fertilizers 

 containing nitrogen only in the ammoniacal 

 form be applied before irrigation, and that 

 nitrate of soda be applied immediately after 

 irrigation. The above considerations assist 

 in explaining why the cane in the spring 

 following heavy rains and cool weather has 

 a yellow unthrifty appearance and needs 

 stimulation. 



The heavy rains have washed out the 

 soluble nitrates, and the cold weather has 

 prevented the nitrifying bacteria from 

 changing insoluble nitrogen to soluble 

 nitrates. The plant is thus deprived of one 

 of its essential food elements, and suffers 

 in consequence. — J. T. Crawley, of the 

 Porto Rico Sugar Planters' Experiment 

 Station, in Porto Rico Progress. 



From most all parts of Cuba come favor- 

 able reports of progress, the general rains 

 recently experienced having proved very 



l)eneficial. The general opinion is that the 

 coming crop will be a good one. — \\ illett 

 & Gray, August 24th. 



